Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/irdma: Fix data race on CQP completion stats CQP completion statistics is read lockesly in irdma_wait_event and irdma_check_cqp_progress while it can be updated in the completion thread irdma_sc_ccq_get_cqe_info on another CPU as KCSAN reports. Make completion statistics an atomic variable to reflect coherent updates to it. This will also avoid load/store tearing logic bug potentially possible by compiler optimizations. [77346.170861] BUG: KCSAN: data-race in irdma_handle_cqp_op [irdma] / irdma_sc_ccq_get_cqe_info [irdma] [77346.171383] write to 0xffff8a3250b108e0 of 8 bytes by task 9544 on cpu 4: [77346.171483] irdma_sc_ccq_get_cqe_info+0x27a/0x370 [irdma] [77346.171658] irdma_cqp_ce_handler+0x164/0x270 [irdma] [77346.171835] cqp_compl_worker+0x1b/0x20 [irdma] [77346.172009] process_one_work+0x4d1/0xa40 [77346.172024] worker_thread+0x319/0x700 [77346.172037] kthread+0x180/0x1b0 [77346.172054] ret_from_fork+0x22/0x30 [77346.172136] read to 0xffff8a3250b108e0 of 8 bytes by task 9838 on cpu 2: [77346.172234] irdma_handle_cqp_op+0xf4/0x4b0 [irdma] [77346.172413] irdma_cqp_aeq_cmd+0x75/0xa0 [irdma] [77346.172592] irdma_create_aeq+0x390/0x45a [irdma] [77346.172769] irdma_rt_init_hw.cold+0x212/0x85d [irdma] [77346.172944] irdma_probe+0x54f/0x620 [irdma] [77346.173122] auxiliary_bus_probe+0x66/0xa0 [77346.173137] really_probe+0x140/0x540 [77346.173154] __driver_probe_device+0xc7/0x220 [77346.173173] driver_probe_device+0x5f/0x140 [77346.173190] __driver_attach+0xf0/0x2c0 [77346.173208] bus_for_each_dev+0xa8/0xf0 [77346.173225] driver_attach+0x29/0x30 [77346.173240] bus_add_driver+0x29c/0x2f0 [77346.173255] driver_register+0x10f/0x1a0 [77346.173272] __auxiliary_driver_register+0xbc/0x140 [77346.173287] irdma_init_module+0x55/0x1000 [irdma] [77346.173460] do_one_initcall+0x7d/0x410 [77346.173475] do_init_module+0x81/0x2c0 [77346.173491] load_module+0x1232/0x12c0 [77346.173506] __do_sys_finit_module+0x101/0x180 [77346.173522] __x64_sys_finit_module+0x3c/0x50 [77346.173538] do_syscall_64+0x39/0x90 [77346.173553] entry_SYSCALL_64_after_hwframe+0x63/0xcd [77346.173634] value changed: 0x0000000000000094 -> 0x0000000000000095

References 4

• git.kernel.org https://git.kernel.org/stable/c/2623ca92cd8f9668edabe9e4f4a3cf77fd7115f2
• git.kernel.org https://git.kernel.org/stable/c/4e1a5842a359ee18d5a9e75097d7cf4d93e233bb
• git.kernel.org https://git.kernel.org/stable/c/bf0f9f65b7fe36ea9d2e23263dcefc90255d7b1f
• git.kernel.org https://git.kernel.org/stable/c/f2c3037811381f9149243828c7eb9a1631df9f9c

Remediation